Driving system for motorcars



Oct. 12, 1965 H. PAPST DRIVING SYSTEM FOR MOTORCARS Filed Oct. 50, 1962 Jn van for man 2 ao fi United States Patent 3,211,249 DRIVING SYSTEM FOR MOTORCARS Hermann Papst, St. Georgen, Black Forest, Germany Filed Oct. 30, 1962, Ser. No. 234,026 Claims priority, application Germany, Nov. 2, 1961, P 28,158 7 Claims. (Cl. 180-65) The present invention relates to an arrangement for motorcars which are driven by internal combustion engmes.

Internal combustion engines for motorcars are usually provided with an electric motor for starting the engine and also with a dynamo for charging the battery. It is also known to use combined electric machines, the socalled dynamotors, for starting .the engine and for chargin g the battery.

Numerous different combinations of internal combustion engines with starters and dyn arn-otors are already known. It has been found that the requirements or desirable qualities of motorcars are only unsatisfactorily met by the known arrangements and combinations of the type set forth.

It is thereiore a main object of this invention to provide an arrangement for the purpose set forth which yields more satisfactory results.

It is another object of this invention to provide for an arrangement of the type mentioned which is comparative- 1y simple in its structure and reliable in operation.

It is a further object of the invention to provide for an arrangement which permits to save valuable time, when in city traffic the internal combustion engine is suddenly stalling in the middle of a street crossing and the motorcar should be moved as quickly as possible out of the danger zone.

It is a still further object of the invention to .avoid the contamination of the air in the garage by exhaust gases of the combustion engine when manoeuvring the motorcar within the garage.

With above objects in view, the arrangement according to the invention includes a gearing for motorcars which is so designed that the shaft connected to the driven car wheels may optionally be driven by the internal combustion engine or by an electric motor.

It is advantageous to arrange the toothed wheels or corresponding transmission elements for connecting the driving shaft with the driven shaft of the gear box so that the driving shaft is driven by the internal combustion engine on one side of said transmission and on the other side by the electric motor. For that purpose it is favorable to arrange the electric motor in front of one end of the driving shaft.

In a preferred embodiment of the invention there is provided a reduction gear between the driving shaft and electric motor. It may be useful to provide an automatic switching system controlling the gear which automatically provides .a higher ratio of transmission when the gear is driven by the electric motor and a lower ratio of trans- 7 mission when the gear is driven by the combustion engine.

When using a dynamo tor for starting, the speed will be considerably stepped down between the dyn amotor and the combustion engine. But if the motorcar is driven in the conventional way by the internal combustion engine, the dynamotor will .be driven with higher speed owing to the change in the ratio of the gear. So even at a low speed of the internal combustion engine the battery will be charged.

Furthermore it is useful to couple the accelerator of the internal combustion engine to the switch of the electric motor.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantages thereof, will be best understood from the following description of a specific embodiment when read in connection with the accompanying drawing, in which:

FIGURE 1 is :a partly sectional plan view of the front axle and the driving mechanism of a motorcar with front drive,

FIGURE 2 is a section along 'a line A.B of FIGURE 1 and shows some details,

One side of the internal combustion engine 2 is tastened to chassis -1 by means of vibration damping elements 3. On the other side of the internal combustion engine there is a casing 4 with flywheel 5 and clutch 6. By operating pedal 7, clutch 6 is disconnected. The internal combustion engine 2 drives the wheels 12, 13 by means of clutch .6, change speed gear 8, differential gear 9 and links 10, 11. The wheels 12, 13 are fastened to chassis 1 in conventional way by swing arms 14, 15.

Gear box 8 comprises a driving shaft 17 with a set of toothed wheels. These toothed wheels engages with a second set of toothed wheels arranged on driven shaft 20 so that each wheel of the second set may be coupled with said driven shaft.

The end of driving shaft 1 7 farthest from clutch 6, is coupled to an electric motor 22 by means of a step-up gearing. Electric motor 22 is fed from battery 23. When switch 25 (for simplification only symbolized by two contacts), which is mechanically coupled to accelerator 24, is closed, electric motor 22 begins to rotateif main switch 0/7 is closed. Electric motor 22 serving as a starter operates the internal combustion engine 2 by means of the gearing 21 (acting now as a step-down gearing), shaft )17, and clutch 6; gear box 8 being generally in the neutral position.

When the internal combustion engine 2 has reached a given speed, a free-wheel in gearing 21 is operated so that electric motor 22 will run idle. When the speed of the internal combustion engine is further increased the speed ratio of gearing 21 is automatically changed. Means for changing the speed ratio are already known and described in German Patent No. 1,073,806 and US. Patent No. 2,886,987. After the speed ratio of the gear has been changed the electric motor 22 is driven by the internal combustion engine 2 with increased speed thus operating as an electric generator and charging battery 23. The usual accessories of the generator, e.g. voltage regulator and switches, are not shown.

Electric motor 22 is provided on its right side with a plane collector 33 and brushes 30 and 31 sliding on the surface of said collector. The position of the electric motor is so chosen that after removing cover 32 the brushes may be easily examined and replaced.

The efiiciency of the electric motor generator 22 is remarkably increased if the parts of its magnetic circuit are not composed in the usual way of a steel-ring with attached pole shoes but consist of single pole pieces 35 having a gap formed in the center of each pole, said gaps being filled by bars 36 of non-magnetic material. The single pole shoes 35 together with the cast-on casing 37 of non-magnetic material, for example light metal, form a rigid unit including the inserted exciting coils. The bars 36 are cast together with casing 37.

In FIGURE 2, 38 signifies the cross-section through the exciting coils and 39 signifies the rear winding heads of said exciting coils which are visible between pole pieces 35 and casing 37. The bars 36 can be seen between the single pole pieces 35.

Driving shaft 17 of gear box 8 is coupled by toothed wheels to a hydraulic pump 40, which may be used for automatically locking the doors when the motorcar is moving or for operating a hydraulic lifting jack when the motorcar is notmoving. V Owing to the provision of step-up gearing 21, the electric motor may be comparatively small. It produces sufficient power even with a shunt-winding. Owing to the unconventional shape of the parts forming the magnetic circuit the transverse field of the rotor is considerably reduced. Therefore, the gap between stator and rotor can be made as small as in conventional induction motors. So it is possible to generate a strong main field even with a small shunt-winding. Therefore, no additional series-Winding is necessary and the winding space of the shunt-winding may be reduced. Thus at given outer dimensions of the electric motor a relatively large diameter of the rotor and an increased power are obtained. Furthermore the weight of the electric motor is remarkably smaller than that of other conventional motors.

Pedal 7 may be locked in the disconnected position of the clutch by means of locking bar 41. In this locked position of pedal 7 the motorcar may be electrically driven over short distances. The internal combustion engine will be used to drive the car over distances which are beyond the driving range of the battery.

By the novel combination of special parts of the gear box with combustion engine and electric motor it is possible to operate the motor car in the following different ways:

(a) With the gear box in neutral position, the internal combustion engine may be started by electric motor 22 and runs idle. Then by operating pedal 7 and clutch 6 the internal combustion engine 2 is disconnected from the gear box, the accelerator is released and a gear is put in. Now pedal 7 is slowly released and the car begins to move in the usual way.

(b) With a gear put in it is also possible to switch on the electric motor by operating the accelerator and to drive the car during starting of the internal combustion engine. Thus valuable time may be saved, e.g. when in city traffic the internal combustion engine is suddenly stalling in the middle of a street crossing and the motorcar should be moved as quickly as possible out of the danger zone.

If stalling of the engine is caused by lack of fuel it is only necessary to disconnect the clutch by operating pedal 7 and then the motorcar may be driven electrically by means of electric motor 22 to the next service station. The capacity of a usual car battery is sufficient to cover a distance of some miles.

(d) Should it be intended to drive the car over a short distance, e.g. manoeuvring the car within a garage,

then it is possible to drive the car electrically as already described (see paragraph 0 above). Therefore, when using a motor car with gear and assembly according to the invention it is not necessary to start the internal combustion engine for manoeuvring within the garage, and

to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention;

What is claimed as new and desired to be secured by Letters Patent is:

'1. A driving system for driving the wheels of a motor car comprising, in combination, an internal combustion engine; a drive shaft; disconnectable main clutch means between said combustion engine and one end of said drive shaft for connecting and disconnecting said one end of said drive shaft to and from said combustion engine; a driven shaft operatively connected to the wheels of the motor car; transmission means between said drive shaft and said driven shaft; an electric motor arranged at the other end of said drive shaft and having a shunt winding; a battery carried by the motor car; circuit means for electrically connecting said battery to said electric motor; and reduction gear means between the other end of said drive shaft and said electric motor and including an automatic switching system which automatically provides a higher transmission ratio 'when the reduction gear means is driven by the electric motor and a lower ratio of transmission when said reduction gear means is driven by said combustion engine, whereby when said combustion engine is connected by said main clutch means to said drive shaft, said engine may be started by said electric motor and the latter be subsequently driven with increased speed by said engine to act as a generator charging the battery, while when said combustion engine is disconnected from said drive shaft the car may be driven at a reduced speed by said electric motor.

2. A system as set forth in claim 1, wherein said electric motor has on its side distant from said drive shaft a plane collector and a pair of brushes engaging said collector and arranged to be easily exchangeable without dismounting the electric motor.

3. A system as set forth in claim 1 and including a hydraulic pump operatively connected to said drive shaft.

4. A driving system for driving the wheels of a motor ,car comprising, in combination, an internal combustion engine; an accelerator for said combustion engine; a drive shaft; disconnectable main clutch means between said combustion engine and one end of said drive shaft for-connecting and disconnecting said one end of said drive shaft to and from said combustion engine; a

driven shaft operatively connected to the wheels of the motor car; transmission means between said drive shaft and said driven shaft; an electric motor arranged at the other end of said drive shaft and having a shunt winding; a battery carried by the motor car; circuit means for electrically connecting said battery to said electric motor;

a switch in said circuit means movable between an open and a closed position, said switch being coupled to said accelerator to be moved to said closed position when said accelerator is actuated so that when the combustion engine is stalling the car will be driven by said electric motor; and reduction gear means between the other end of said drive shaft and said electric motor and including an automatic switching system which automatically provides a higher transmission ratio when the reduction gear means is driven by the electric motor and a lower ratio of transmission when said reduction gear means is driven by said combustion engine, whereby when said combustion engine is connected by said main clutch means to said drive shaft, said engine may be started by said electric motor and the latter be subsequently driven with increased speed by said engine to act as a generator charging the'battery, while when said combustion engine is disconnected from said drive shaft the car may be driven at a reduced speed by said electric motor.

5. A driving system for driving the wheels of a motor car comprising, in combination, an internal combustion engine; a drive shaft; disconnectable main clutch means between said combustion engine and one end of said drive shaft for connecting and disconnecting said one end of said drive shaft to and from said combustion engine; means cooperating with said main clutch means for m t ning t e Same in disengaged position; a driven shaft operatively connected to the wheels of the motor car; transmission means between said drive shaft and said driven shaft; an electric motor arranged at the other end of said drive shaft and having a shunt winding; a battery carried by the motor car; circuit means for electrically connecting said battery to said electric motor; and reduction gear means between the other end of said drive shaft and said electric motor and including an automatic switching system which automatically provides a higher transmission ratio when the reduction gear means is driven by the electric motor and a lower ratio of transmission when said reduction gear means is driven by said combustion engine, whereby when said combustion engine is connected by said main clutch means to said drive shaft, said engine may be started by said electric motor and the latter be subsequently driven with increased speed by said engine to act as a generator charging the battery, while when said combustion engine is disconnected from said drive shaft the car may be driven at a reduced speed by said electric motor.

6. A driving system for driving the wheels of a motor car comprising, in combination, an internal combustion engine; a drive shaft; disconnectable main clutch means between said combustion engine and one end of said drive shaft for connecting and disconnecting said one end of said drive shaft to and from said combustion engine; a driven shaft operatively connected to the wheels of the motor car; transmission means between said drive shaft and said driven shaft; an electric motor arranged at the other end of said drive shaft and having a shunt winding and a stator having a plurality of pole pieces each having in the center thereof a wedge-shaped gap diverging in outward direction; a battery carried by the motor car; circuit means for electrically connecting said battery to said electric motor; and reduction gear means between the other end of said drive shaft and said electric motor and including an automatic switching system which automatically provides a higher transmission ratio when the reduction gear means is driven by the electric motor and a lower ratio of transmission when said reduction gear means is driven by said combustion engine, whereby when said combustion engine is connected by said main clutch means to said drive shaft, said engine may be started by said electric motor and the latter be subsequently driven with increased speed by said engine to act as a generator charging the battery, while when said combustion engine is disconnected from said drive shaft the car may be driven at a reduced speed by said electric motor.

7. A driving system for driving the wheels of a motor car comprising, in combination, an internal combustion engine; a drive shaft; disconnectable main clutch means between said combustion engine and one end of said drive shaft for connecting and disconnecting said one end of said drive shaft to and from said combustion engine; a driven shaft operatively connected to the wheels of the motor car; transmission means between said drive shaft and said driven shaft; an electric motor arranged at the other end of said drive shaft and having only a shunt winding, and a stator having a plurality of pole pieces each having in the center thereof a wedge-shaped gap diverging in outward direction; a battery carried by the motor car; circuit means for electrically connecting said battery to said electric motor; and reduction gear means between the other end of said drive shaft and said electric motor and including an automatic switching system which automatically provides a higher transmission ratio when the reduction gear means is driven by the electric motor and a lower ratio of transmission when said reduction gear means is driven by said combustion engine, whereby when said combustion engine is connected by said main clutch means to said drive shaft, said engine may be started by said electric motor and the latter be subsequently driven with increased speed by said engine to act as a generator charging the battery, while when said combustion engine is disconnected from said drive shaft the car may be driven at a reduced speed by said electric motor.

References Cited by the Examiner UNITED STATES PATENTS 467,318 1/92 Thomson 310-237 X 799,851 9/05 Hood 290-19 1,323,500 12/19 Stephenson 290-19 1,822,198 9/31 Buss 74-532 2,303,293 11/42 Thomas 310-187 X 2,885,016 5/59 Ayers -65 X 2,886,987 5/59 Papst 74-810 FOREIGN PATENTS 393,311 5/33 Great Britain.

614,914 12/48 Great Britain.

734,399 8/32 France.

BENJAMIN HERSH, Primary Examiner. A. HARRY LEVY, PHILIP ARNOLD, Examiners. 

1. A DRIVING SYSTEM FOR DRIVING THE WHEELS OF A MOTOR CAR COMPRISING, IN COMBINATION, AN INTERNAL COMBUSTION ENGINE; A DRIVE SHAFT; DISCONNECTABLE MAIN CLUTCH MEANS BETWEEN SAID COMBUSTION ENGINE AND ONE END OF SAID DRIVE SHAFT FOR CONNECTING AND DISCONNECTING SAID ONE END OF SAID DRIVE SHAFT TO AND FROM SAID COMBUSTION ENGINE; A DRIVEN SHAFT OPERATIVELY CONNECTED TO THE WHEELS OF THE MOTOR CAR; TRANSMISION MEANS BETWEEN SAID DRIVE SHAFT AND SAID DRIVEN SHAFT; AND ELECTRIC MOTOR ARRANGED AT THE OTHER END OF SAID DRIVE SHAFT AND HAVING A SHUNT WINDING; A BATTERY CARRIED BY THE MOTOR CAR; CIRCUIT MEANS FOR ELECTRICALLY CONNECTING SAID BATTERY TO SAID ELECTRIC MOTOR; AND REDUCTION GEAR MEANS BETWEEN THE OTHER END OF SAID DRIVE SHAFT AND SAID ELECTRIC MOTOR INCLUDING AN AUTOMATIC SWITCHING SYSTEM WHICH AUTOMATICALLY PROVIDES A HIGHER TRANSMISSION RATIO WHEN THE REDUCTION GEAR MEANS IS DRIVEN BY THE ELECTRIC MOTOR AND A LOWER RATIO OF TRANSMISSION WHEN SAID REDUCTION GEAR MEANS IS DRIVEN BY SAID COMBUSTION ENGINE, WHEREBY WHEN SAID COMBUSTION ENGINE IS CONNECTED BY SAID MAIN CLUTCH MEANS TO SAID DRIVE SHAFT, SAID ENGINE MAY BE STARTED BY SAID ELECTRIC MOTOR AND THE LATTER BE SUBSQUENTLY DRIVEN WITH INCREASED SPEED BY SAID ENGINE TO ACT AS A GENERATOR CHARGING THE BATTERY, WHILE WHEN THE COMBUSTION ENGINE IS DISCONNECTED FROM SAID DRIVE SHAFT THE CAR MAY BE DRIVEN AT A REDUCED SPEED BY SAID ELECTRIC MOTOR. 